Dry Cold Forging of Pure Titanium Wire to Thin Plate with Use of β-SiC Coating Dies

Tatsuhiko Aizawa; Tomoaki Yoshino; Tatsuya Fukuda; Tomomi Shiratori

doi:10.3390/ma13173780

Dry Cold Forging of Pure Titanium Wire to Thin Plate with Use of β-SiC Coating Dies

Materials (Basel). 2020 Aug 27;13(17):3780. doi: 10.3390/ma13173780.

Authors

Tatsuhiko Aizawa¹, Tomoaki Yoshino², Tatsuya Fukuda³, Tomomi Shiratori⁴

Affiliations

¹ Surface Engineering Design Laboratory, Shibaura Institute of Technology, Tokyo 144-0045, Japan.
² Komatsu-Seiki Kosakusho, Co., Ltd., Nagano 392-0022, Japan.
³ Tokai Engineering Service, Co., Ltd., Gifu 504-0852, Japan.
⁴ Faculty of Engineering, University of Toyama, Toyama 939-8202, Japan.

Abstract

Dense β-SiC coating with 3C-structure was utilized as a dry cold forging punch and core-die. Pure titanium T328H wires of industrial grade II were employed as a work material. No adhesion or galling of metallic titanium was detected on the contact interface between this β-SiC die and titanium work, even after this continuous forging process, up to a reduction in thickness by 70%. SEM (Scanning Electron Microscopy) and EDX (Electron Dispersive X-ray spectroscopy) were utilized to analyze this contact interface. A very thin titanium oxide layer was in situ formed in the radial direction from the center of the contact interface. Isolated carbon from β-SiC agglomerated and distributed in dots at the center of the initial contact interface. Raman spectroscopy was utilized, yielding the discovery that this carbon is unbound as a free carbon or not bound in SiC or TiC and that intermediate titanium oxides are formed with TiO₂ as a tribofilm.

Keywords: SiC-coated SiC die; carbon isolation; contact interface; dry cold forging; high reduction rate; surface area extension rate; titanium; titanium oxide debris film.